This invention concerns attaching drive motors to engine cooling fan systems.
Such systems include a fan attached to a motor which is in turn attached to the motor mount of a fan housing which holds it in place and positions the motor/fan assembly to operate with a heat exchanger. The attachment of the motor to the motor mounting structure is subject to a number of considerations. For servicing, the attachment should be capable of easy assembly and disassembly, e.g. with hand tools. It must also undergo many hours of exposure to vibration and temperature cycling without developing looseness or rattling between the motor and motor mounting structure. Additionally, the attachment should function despite manufacturing variances inherent in mass-produced parts.
Many existing attachment systems use metal fasteners such as screws, studs, nuts, and rivets in order to satisfy these requirements. These fasteners add cost to the product and increase part count. In a market where demands on quality are increasing, they may also introduce additional failure modes, some of which are difficult to detect. Measures typically are taken to insure that parts are not shipped with fasteners which are missing, incorrectly selected, or incorrectly tightened. Finally, these fasteners must be supplied with replacement parts, to insure the integrity of repairs.